[PATCH perf/core 3/4] perf-probe: Fix to cut off incompatible chars from group name

[Masami Hiramatsu <mhiramat@kernel.org>]

Cut off the characters which can not use for group name of uprobes
when making it based on executable filename.

For example, if the exec name is libstdc++.so, without this fix
perf probe generates "probe_libstdc++" as the group name, but
it is failed to set because '+' can not be used for group name.

With this fix perf accepts only alphabet, number or '_' for group
name, thus perf generates "probe_libstdc" as the group name.

E.g. with this fix, you can see the event name has no "+".
  ----
  $ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open
  p:probe_libstdc/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
  p:probe_libstdc/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
  p:probe_libstdc/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
  p:probe_libstdc/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
  p:probe_libstdc/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
  ----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 tools/perf/util/probe-event.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index bc60ce4..fcfbef0 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -213,9 +213,13 @@ static int convert_exec_to_group(const char *exec, char **result)
 		goto out;
 	}
 
-	ptr2 = strpbrk(ptr1, "-._");
-	if (ptr2)
-		*ptr2 = '\0';
+	for (ptr2 = ptr1; ptr2 != '\0'; ptr2++) {
+		if (!isalnum(*ptr2) && *ptr2 != '_') {
+			*ptr2 = '\0';
+			break;
+		}
+	}
+
 	ret = e_snprintf(buf, 64, "%s_%s", PERFPROBE_GROUP, ptr1);
 	if (ret < 0)
 		goto out;